The present invention relates to the harvesting of blood vessels and, more particularly, to methods and apparatus for endoscopic dissection of sections of blood vessels, such as saphenous veins, for use as a coronary artery bypass graft.
It is common during various surgical procedures, and most particularly during coronary artery bypass grafting (CABG), to remove or “harvest” 0 a blood vessel or vessel section, such as an artery or vein, from its natural location in a patient's body and to use it elsewhere in the body. In CABG surgery, the blood vessel is used to form a bypass between an arterial blood source and the coronary artery that is to be bypassed. Often an artery proximate the heart, such as one of the internal mammary arteries, can be used as the bypass graft, although the saphenous veins in the legs, or a radial artery in an arm can also be used as well.
The conventional surgical procedure used to harvest a section of the saphenous vein, or the like, for use in the CABG surgery involves making a continuous incision in the leg for the full length of the desired vein section in order to provide adequate exposure for visualizing the vein and for introducing surgical instruments to sever, cauterize and ligate the tissue and side branches of the vein. The incision must then be closed by suturing or stapling along its length.
Less-invasive techniques for harvesting blood vessels have also been developed which employ only two small incisions, generally one at each end of the section of vessel to be removed. Primary dissection occurs by introduction of one or more surgical instruments through a first incision to create a working space and separate the vein from the surrounding tissue. Then further instruments are introduced into the generally limited working space to dissect the blood vessel from the connective tissue surrounding the section to be harvested. The side branches of the blood vessel are also clipped and/or cauterized. In order to remove the desired section of the blood vessel, a second small incision, or stab wound, is made at the distal end thereof and the distal end of the blood vessel section is ligated. The proximal end of the blood vessel section is then also ligated, thereby allowing the desired section to be completely removed through the first incision. An endoscopic instrument is generally required for such a procedure to enhance visualization of the vessel and the surrounding tissue and to properly position the surgical instrument. Example of such endoscopic instruments for harvesting blood vessels are shown in U.S. Pat. No. 6,193,653 to Evans et al. and U.S. Pat. No. 6,019,771 to Bennett et al.
These types of less invasive techniques reduce the overall length of the incision, as well as the trauma to the blood vessel section and the surrounding tissue. The introduction of a plurality of surgical instruments through the incision, however, may still cause some irritation or damage to the vessel which must then be repaired before it can be used as a graft.
Accordingly, it would be desirable to have a vessel harvesting device and procedure that minimizes the number of surgical instruments that must be inserted into the patient's body and that provides for more precise manipulation of the blood vessel by a surgeon.